The danger and damage of ultraviolet light, especially from the sun, is well documented, including the danger to the human eye.
But I am finding it hard to find information on the danger of infrared light To make a long story short, I am building a high-power infrared flash light, because I discovered all digital cameras can see infrared light as purple/white, even tv remotes. Now this is a 3 watt infrared LED, very very high brightness, if it were white, it would be bright enough to light up an entire room at night. I'm smart enough not to stare directly into the LED while it is on.
But every time I test the LED, even pointing it away from me and never looking directly into it, even if I only have it on for 10 seconds or so, I get a headache in the back of my head afterwards that lasts about 10 or 20 minutes, and my eyes feel like they kinda hurt (like the feeling you get when you wake up and turn on a bright light) for an hour or two.
Is even looking at the reflected infrared light off of surfaces such as walls dangerous? Or is there no documented effect on the eyes from bright infrared light, and the headaches/eye pain are likely coincidence/placebo?